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  <title>为类创建别名</title>
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  <div id="layout-content"><div id="function.class-alias" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">class_alias</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.3.0, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">class_alias</span> &mdash; <span class="dc-title">为类创建别名</span></p>

 </div>
 <div class="refsect1 description" id="refsect1-function.class-alias-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>class_alias</strong></span>(<span class="methodparam"><span class="type">string</span> <code class="parameter">$class</code></span>, <span class="methodparam"><span class="type">string</span> <code class="parameter">$alias</code></span>, <span class="methodparam"><span class="type">bool</span> <code class="parameter">$autoload</code><span class="initializer"> = <strong><code>true</code></strong></span></span>): <span class="type">bool</span></div>

  <p class="para rdfs-comment">
   基于用户定义的类 <code class="parameter">class</code> 创建别名 <code class="parameter">alias</code>。
   这个别名类和原有的类完全相同。
  </p>
 </div>

 <div class="refsect1 parameters" id="refsect1-function.class-alias-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    
     <dt>
<code class="parameter">class</code></dt>

     <dd>

      <p class="para">
       原有的类。
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">alias</code></dt>

     <dd>

      <p class="para">
       类的别名。
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">autoload</code></dt>

     <dd>

      <p class="para">
       如果原始类没有加载，是否使用自动加载（autoload）。
      </p>
     </dd>

    
   </dl>

  </p>
 </div>

 <div class="refsect1 returnvalues" id="refsect1-function.class-alias-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>true</code></strong>， 或者在失败时返回 <strong><code>false</code></strong>。
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.class-alias-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-5021">
    <p><strong>示例 #1 <span class="function"><strong>class_alias()</strong></span> 例子</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">foo&nbsp;</span><span style="color: #007700">{&nbsp;}<br /><br /></span><span style="color: #0000BB">class_alias</span><span style="color: #007700">(</span><span style="color: #DD0000">'foo'</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'bar'</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$b&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">bar</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">//&nbsp;对象是相同的<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">==&nbsp;</span><span style="color: #0000BB">$b</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">===&nbsp;</span><span style="color: #0000BB">$b</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">instanceof&nbsp;</span><span style="color: #0000BB">$b</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;类是相同的<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">instanceof&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">instanceof&nbsp;</span><span style="color: #0000BB">bar</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$b&nbsp;</span><span style="color: #007700">instanceof&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$b&nbsp;</span><span style="color: #007700">instanceof&nbsp;</span><span style="color: #0000BB">bar</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
bool(true)
bool(false)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
</pre></div>
    </div>
   </div>
  </p>
 </div>

 <div class="refsect1 seealso" id="refsect1-function.class-alias-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.get-parent-class.html" class="function" rel="rdfs-seeAlso">get_parent_class()</a> - 检索对象或者类的父级类名</span></li>
    <li class="member"><span class="function"><a href="function.is-subclass-of.html" class="function" rel="rdfs-seeAlso">is_subclass_of()</a> - 检查对象是否继承或者实现（implement）此类</span></li>
   </ul>
  </p>
 </div>

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